/* This is a public domain general purpose hash table package written by Peter Moore @ UCB. */

/* static	char	sccsid[] = "@(#) st.c 5.1 89/12/14 Crucible"; */

#include <stdlib.h>
#include <string.h>
#include "st.h"

/* js modification, add include gc.h */
#include "gc.h"

typedef struct st_table_entry st_table_entry;

struct st_table_entry
{
    unsigned int hash;
    st_data_t key;
    st_data_t record;
    st_table_entry *next;
};

#define ST_DEFAULT_MAX_DENSITY 5
#define ST_DEFAULT_INIT_TABLE_SIZE 11

/*
 * DEFAULT_MAX_DENSITY is the default for the largest we allow the
 * average number of items per bin before increasing the number of
 * bins
 *
 * DEFAULT_INIT_TABLE_SIZE is the default for the number of bins
 * allocated initially
 *
 */
static int numcmp(long, long);
static int numhash(long);
static struct st_hash_type type_numhash =
    {
        numcmp,
        numhash,
};

extern int strcmp(const char *, const char *);
static int strhash(const char *);
static struct st_hash_type type_strhash =
    {
        strcmp,
        strhash,
};

static void rehash(st_table *);

/* js modification, change malloc to js_alloc */
/* #define alloc(type) (type*)malloc((unsigned)sizeof(type))
#define Calloc(n,s) (char*)memset(js_alloc((n)*(s)), 0, (n)*(s))*/
#define Calloc(n, s) (char *)js_alloc((n) * (s))
#define alloc(type) (type *)js_alloc((unsigned)sizeof(type))

#define EQUAL(table, x, y) ((x) == (y) || (*table->type->compare)((x), (y)) == 0)

#define do_hash(key, table) (unsigned int)(*(table)->type->hash)((key))
#define do_hash_bin(key, table) (do_hash(key, table) % (table)->num_bins)

/*
 * MINSIZE is the minimum size of a dictionary.
 */

#define MINSIZE 8

/*
Table of prime numbers 2^n+a, 2<=n<=30.
*/
static long primes[] =
    {
        8 + 3,
        16 + 3,
        32 + 5,
        64 + 3,
        128 + 3,
        256 + 27,
        512 + 9,
        1024 + 9,
        2048 + 5,
        4096 + 3,
        8192 + 27,
        16384 + 43,
        32768 + 3,
        65536 + 45,
        131072 + 29,
        262144 + 3,
        524288 + 21,
        1048576 + 7,
        2097152 + 17,
        4194304 + 15,
        8388608 + 9,
        16777216 + 43,
        33554432 + 35,
        67108864 + 15,
        134217728 + 29,
        268435456 + 3,
        536870912 + 11,
        1073741824 + 85,
        0};

static int
    new_size(size) unsigned int size;
{
    unsigned int i;

#if 0
    for (i=3; i<31; i++) {
        if ((1<<i) > size) return 1<<i;
    }
    return -1;
#else
    unsigned int newsize;

    for (i = 0, newsize = MINSIZE;
         i < sizeof(primes) / sizeof(primes[0]);
         i++, newsize <<= 1)
    {
        if (newsize > size)
            return primes[i];
    }
    /* Ran out of polynomials */
    return -1; /* should raise exception */
#endif
}

st_table *
    st_init_table_with_size(type, size) struct st_hash_type *type;
int size;
{
    st_table *tbl;

#ifdef HASH_LOG
    if (init_st == 0)
    {
        init_st = 1;
        atexit(stat_col);
    }
#endif

    size = new_size(size); /* round up to prime number */

    tbl = alloc(st_table);
    tbl->type = type;
    tbl->num_entries = 0;
    tbl->num_bins = size;
    tbl->bins = (st_table_entry **)Calloc(size, sizeof(st_table_entry *));

    return tbl;
}

st_table *
    st_init_table(type) struct st_hash_type *type;
{
    return st_init_table_with_size(type, 0);
}

st_table *
st_init_numtable(void)
{
    return st_init_table(&type_numhash);
}

st_table *
    st_init_numtable_with_size(size) int size;
{
    return st_init_table_with_size(&type_numhash, size);
}

st_table *
st_init_strtable(void)
{
    return st_init_table(&type_strhash);
}

st_table *
    st_init_strtable_with_size(size) int size;
{
    return st_init_table_with_size(&type_strhash, size);
}

void
    st_free_table(table)
        st_table *table;
{
    register st_table_entry *ptr, *next;
    int i;

    for (i = 0; i < table->num_bins; i++)
    {
        ptr = table->bins[i];
        while (ptr != 0)
        {
            next = ptr->next;
            /* js modification, remove free
            free(ptr); */
            ptr = next;
        }
    }

    /* js modification, remove free
    free(table->bins);
    free(table); */
}

#define PTR_NOT_EQUAL(table, ptr, hash_val, key) \
    ((ptr) != 0 && (ptr->hash != (hash_val) || !EQUAL((table), (key), (ptr)->key)))

#ifdef HASH_LOG
#define COLLISION collision++
#else
#define COLLISION
#endif

#define FIND_ENTRY(table, ptr, hash_val, bin_pos)                  \
    do                                                             \
    {                                                              \
        bin_pos = hash_val % (table)->num_bins;                    \
        ptr = (table)->bins[bin_pos];                              \
        if (PTR_NOT_EQUAL(table, ptr, hash_val, key))              \
        {                                                          \
            COLLISION;                                             \
            while (PTR_NOT_EQUAL(table, ptr->next, hash_val, key)) \
            {                                                      \
                ptr = ptr->next;                                   \
            }                                                      \
            ptr = ptr->next;                                       \
        }                                                          \
    } while (0)

int
    st_lookup(table, key, value)
        st_table *table;
register st_data_t key;
st_data_t *value;
{
    unsigned int hash_val, bin_pos;
    register st_table_entry *ptr;

    hash_val = do_hash(key, table);
    FIND_ENTRY(table, ptr, hash_val, bin_pos);

    if (ptr == 0)
    {
        return 0;
    }
    else
    {
        if (value != 0)
            *value = ptr->record;
        return 1;
    }
}

#define ADD_DIRECT(table, key, value, hash_val, bin_pos)                     \
    do                                                                       \
    {                                                                        \
        st_table_entry *entry;                                               \
        if (table->num_entries / (table->num_bins) > ST_DEFAULT_MAX_DENSITY) \
        {                                                                    \
            rehash(table);                                                   \
            bin_pos = hash_val % table->num_bins;                            \
        }                                                                    \
        entry = alloc(st_table_entry);                                       \
        entry->hash = hash_val;                                              \
        entry->key = key;                                                    \
        entry->record = value;                                               \
        entry->next = table->bins[bin_pos];                                  \
        table->bins[bin_pos] = entry;                                        \
        table->num_entries++;                                                \
    } while (0)

int
    st_insert(table, key, value) register st_table *table;
register st_data_t key;
st_data_t value;
{
    unsigned int hash_val, bin_pos;
    register st_table_entry *ptr;

    hash_val = do_hash(key, table);
    FIND_ENTRY(table, ptr, hash_val, bin_pos);

    if (ptr == 0)
    {
        ADD_DIRECT(table, key, value, hash_val, bin_pos);
        return 0;
    }
    else
    {
        ptr->record = value;
        return 1;
    }
}

void
    st_add_direct(table, key, value)
        st_table *table;
st_data_t key;
st_data_t value;
{
    unsigned int hash_val, bin_pos;

    hash_val = do_hash(key, table);
    bin_pos = hash_val % table->num_bins;
    ADD_DIRECT(table, key, value, hash_val, bin_pos);
}

static void
    rehash(table) register st_table *table;
{
    register st_table_entry *ptr, *next, **new_bins;
    int i, old_num_bins = table->num_bins, new_num_bins;
    unsigned int hash_val;

    new_num_bins = new_size(old_num_bins + 1);
    new_bins = (st_table_entry **)Calloc(new_num_bins, sizeof(st_table_entry *));

    for (i = 0; i < old_num_bins; i++)
    {
        ptr = table->bins[i];
        while (ptr != 0)
        {
            next = ptr->next;
            hash_val = ptr->hash % new_num_bins;
            ptr->next = new_bins[hash_val];
            new_bins[hash_val] = ptr;
            ptr = next;
        }
    }
    /* js modification, remove free
    free(table->bins); */
    table->num_bins = new_num_bins;
    table->bins = new_bins;
}

st_table *
    st_copy(old_table)
        st_table *old_table;
{
    st_table *new_table;
    st_table_entry *ptr, *entry;
    int i, num_bins = old_table->num_bins;

    new_table = alloc(st_table);
    if (new_table == 0)
    {
        return 0;
    }

    *new_table = *old_table;
    new_table->bins = (st_table_entry **)
        Calloc((unsigned)num_bins, sizeof(st_table_entry *));

    if (new_table->bins == 0)
    {
        /* js modification, remove free
        free(new_table); */
        return 0;
    }

    for (i = 0; i < num_bins; i++)
    {
        new_table->bins[i] = 0;
        ptr = old_table->bins[i];
        while (ptr != 0)
        {
            entry = alloc(st_table_entry);
            if (entry == 0)
            {
                /* js modification, remove free
                free(new_table->bins);
                free(new_table); */
                return 0;
            }
            *entry = *ptr;
            entry->next = new_table->bins[i];
            new_table->bins[i] = entry;
            ptr = ptr->next;
        }
    }
    return new_table;
}

int
    st_delete(table, key, value) register st_table *table;
register st_data_t *key;
st_data_t *value;
{
    unsigned int hash_val;
    st_table_entry *tmp;
    register st_table_entry *ptr;

    hash_val = do_hash_bin(*key, table);
    ptr = table->bins[hash_val];

    if (ptr == 0)
    {
        if (value != 0)
            *value = 0;
        return 0;
    }

    if (EQUAL(table, *key, ptr->key))
    {
        table->bins[hash_val] = ptr->next;
        table->num_entries--;
        if (value != 0)
            *value = ptr->record;
        *key = ptr->key;

        /* js modification, remove free
        free(ptr); */
        return 1;
    }

    for (; ptr->next != 0; ptr = ptr->next)
    {
        if (EQUAL(table, ptr->next->key, *key))
        {
            tmp = ptr->next;
            ptr->next = ptr->next->next;
            table->num_entries--;
            if (value != 0)
                *value = tmp->record;
            *key = tmp->key;
            /* js modification, remove free
            free(tmp); */
            return 1;
        }
    }

    return 0;
}

int
    st_delete_safe(table, key, value, never) register st_table *table;
register st_data_t *key;
st_data_t *value;
st_data_t never;
{
    unsigned int hash_val;
    register st_table_entry *ptr;

    hash_val = do_hash_bin(*key, table);
    ptr = table->bins[hash_val];

    if (ptr == 0)
    {
        if (value != 0)
            *value = 0;
        return 0;
    }

    for (; ptr != 0; ptr = ptr->next)
    {
        if ((ptr->key != never) && EQUAL(table, ptr->key, *key))
        {
            table->num_entries--;
            *key = ptr->key;
            if (value != 0)
                *value = ptr->record;
            ptr->key = ptr->record = never;
            return 1;
        }
    }

    return 0;
}

static int
    delete_never(key, value, never)
        st_data_t key,
    value, never;
{
    if (value == never)
        return ST_DELETE;
    return ST_CONTINUE;
}

void
    st_cleanup_safe(table, never)
        st_table *table;
st_data_t never;
{
    int num_entries = table->num_entries;

    st_foreach(table, delete_never, never);
    table->num_entries = num_entries;
}

int
    st_foreach(table, func, arg)
        st_table *table;
int (*func)();
st_data_t arg;
{
    st_table_entry *ptr, *last, *tmp;
    enum st_retval retval;
    int i;

    for (i = 0; i < table->num_bins; i++)
    {
        last = 0;
        for (ptr = table->bins[i]; ptr != 0;)
        {
            retval = (*func)(ptr->key, ptr->record, arg);
            switch (retval)
            {
            case ST_CHECK: /* check if hash is modified during iteration */
                tmp = 0;
                if (i < table->num_bins)
                {
                    for (tmp = table->bins[i]; tmp; tmp = tmp->next)
                    {
                        if (tmp == ptr)
                            break;
                    }
                }
                if (!tmp)
                {
                    /* call func with error notice */
                    return 1;
                }
                /* fall through */
            case ST_CONTINUE:
                last = ptr;
                ptr = ptr->next;
                break;
            case ST_STOP:
                return 0;
            case ST_DELETE:
                tmp = ptr;
                if (last == 0)
                {
                    table->bins[i] = ptr->next;
                }
                else
                {
                    last->next = ptr->next;
                }
                ptr = ptr->next;
                /* js modification, remove free
                    free(tmp); */
                table->num_entries--;
            }
        }
    }
    return 0;
}

static int
    strhash(string) register const char *string;
{
    register int c;

#ifdef HASH_ELFHASH
    register unsigned int h = 0, g;

    while ((c = *string++) != '\0')
    {
        h = (h << 4) + c;
        if (g = h & 0xF0000000)
            h ^= g >> 24;
        h &= ~g;
    }
    return h;
#elif defined(HASH_PERL)
    register int val = 0;

    while ((c = *string++) != '\0')
    {
        val += c;
        val += (val << 10);
        val ^= (val >> 6);
    }
    val += (val << 3);
    val ^= (val >> 11);

    return val + (val << 15);
#else
    register int val = 0;

    while ((c = *string++) != '\0')
    {
        val = val * 997 + c;
    }

    return val + (val >> 5);
#endif
}

static int numcmp(x, y) long x, y;
{
    return x != y;
}

static int numhash(n) long n;
{
    return n;
}
